1. Field of the Invention
The present invention is related to a secure device for a heat sink and CPU and particularly to a secure device for a heat sink capable of dissipating heat of a central processing unit (CPU).
2. Brief Description of the Related Art
The electronic information product such as the computer has been widely applied in our daily life. Due to demand, the electronic information technology has developed rapidly to upgrade operation speed and increase data access capacity. Accordingly, high heat generates along the components in the electronic information product operating with high speed.
Taking the host unit of the computer as an example, the CPU produces a large part of the heat generation in the computer. Besides, the heat accumulation of the CPU exceeding the allowable limit results in breaking down of the computer. Further, in order to solve problem related to electromagnetic interference, the host unit is enclosed by a case, which hinders heat dissipation of the computer. How to guide heat from the CPU and other electronic components fast is an important subject.
The conventional way to dissipate heat of the CPU is to place a side of a heat sink on top of the CPU. The heat sink provides a plurality of cooling fins at another side thereof to transmit the heat. Further, a fan is provided in association with the heat sink to dissipate the heat rapidly. Hence, the CPU and the heat sink have to keep contact with each other tightly. In case of poor contact between the CPU and the heat sink, heat resistance increases and degrades the heat dissipation largely. A conventional secure device 7 for a CPU shown in FIGS. 1 and 2 provides an engaging lever 71 and the engaging lever 71 provides a vertical part 710 at an end thereof. The free end of the vertical part 710 provides a through hole 711 to engage with a projection (not shown) of the fixing base H. Another end of the engaging lever 71 provides two slots 712 for being pierced with an end of the hanging part 72. The hanging part 72 provides fitting holes 721 at the end thereof to join the operation member O with a pivot S passing through an eccentric hole O1 and the fixing holes 721. Once the operation member O is stirred, the engaging hole 722 of the hanging part 72 engages with another projection H1 of the fixing base. In this way, the heat sink R is secured to the CPU C.
The preceding conventional secure device 7 employing resisting force created by an eccentric cam has the following deficiencies:
(1) The operation member O and the hanging part 72 are connected to each other in an immobile way such that the vertical motion of the hanging part 72 depends on the operation member O producing displacement of releasing section or fixing section by means of eccentric cam. However, the eccentric cam has a lower dead point and increments of different curvatures such that it may result in dropping off thereof and in shocks. As a result, the engaging lever 71 fails to operate the hanging part 72 or is detached from the hanging part 72.
(2) The operation member O may easy to become inclined after the secure device 7 engaging the heat sink.
(3) The CPU C undesirably contacts with the heat sink R to increase the thermal resistance so as to influence effect of heat dissipation greatly.